Vol. 51 No. 10 
BULLETIN 
OF THE 
TORREY BOTANICAL CLUB 
OCTOBER, 1924 
Some Senecioid Genera—II* 
P. A. RYDBERG 
ODONTOTRICHUM Zucc. Abh. Baier. Akad. Wiss. 
1832: 311. -1832. 
Sciadoseris Kunze, Bot. Zeit. 9: 349. 1851. 
Mesoneuris A. Gray, Proc. Am. Acad. 8: 661. 1873. 
This genus was proposed by Zuccarini and described from a 
plant collected in Mexico, the type being O. cirsiifelium. Ap- 
parently the same plant was collected by Andrieux and described 
by De Candolle as Cacalia cervariaefolia with the remark that 
it perhaps should be separated generically. Hemsley transferred 
the latter to Senecio. Gray’s Mesoneuris bipinnatifida was 
based on a closely related species. From the description Kunze’s 
Sciadcseris seems to be the same genus, but his type S. vaginata 
was described from cultivated material in the botanic garden at 
Berlin. The origin was unknown but Kunze suggested Peru. 
If from Mexico, it might be the same as Gray’s plant. In the 
two species, which constitute the genus as originally character- 
ized, the style branches are oblong or slightly clavate, merely 
obtuse, and the terminal hair-pencil characteristic of Senecio is 
poorly developed. I hardly think that this character alone 
should be regarded as being enough to base a genus on. I have 
therefore extended the genus, rather than propose a new genus 
for the larger group of species with truly senecioid style, but 
otherwise closely related. This group includes more than half 
of the Mexican species referred to Cacalia. Most of these are of 
* Continued from Bull. Torrey Club 51: 378. 1924. 
[The BuLLETIN for September (51: 369-408) was issued Sept. 18, 1924.] 
409 
